If a business already provide “Free WiFi” with a shared password which is told to the guest, it’s time to go next-level.
Separating Guest WiFi from business (private) network is the first step. Existing WiFi can be renamed to “Staff WiFi” and secured with a password. If you are using ADSL modem which can not be upgraded, you will add additional router that will serve guests. Additional “Free WiFi” network will be created without a password, so that guests can easily connect without a password. Once connected, they will get a splash page asking them to login, watch video ad, complete satisfaction survey etc. Guests will connect easily and your staff will do their real job instead of telling passwords and helping customers to connect.